IV] 



PEZIZALES 



l 2 I 



multicellular archicarps, each rather like the single scolecite of Ascobolus. 

 The cells are not connected by pores, and ascogenous hyphae arise from 

 several in each archicarp. 



In R.brunneus Dangeard reports a single archicarp, consisting of a short, 

 somewhat twisted branch. Ramlow has also recorded a single archicarp in 

 A', polysporus and Barker in an unnamed species. Overton has made some 

 study of tin- development of the numerous spores in A'. Pelletieri. The 

 ascus nucleus divides as usual to form eight free nuclei, these undergo a 

 period of rest and growth and then divide further till thirty-two free nuclei 

 are formed. .Around these the spores are delimited in the usual way. 



Thelebolus stercoreus has a mycelium of uninucleate cells, from one of 

 which the archicarp arises as a thick branch containing a single nucleus. 

 Later two, four, and finally eight, are seen (fig. 85), and then septation takes 



My. S4. Thelebolus stercorals Tde. ; a. young ascocarp with binucleate asci ; b. ascus 

 containing fusion nucleus, both x8io; after Ramlow. 



place, so that a row of cells is formed. Most of these are uninucleate, but 

 one contains two nuclei (fig. 84*2); it enlarges and becomes the single ascus; 

 in it the two nuclei fuse (fig. 84^). The definitive nucleus divides karyo- 

 kinetically, sometimes as many as ten times, so that 1042 nuclei are formed. 



Fig. 8= 



Thelebolus stercorals, Tde.; development of archicarp. 17=0; after. Ramlow. 



Spore-formation takes place apparently in the usual way. The wall of the 

 ripe ascus is about 2/x thick, but a thinner region is present at the apex, so 

 that a concave papilla is differentiated, which is concerned in the dehiscence 

 of the ascus. A sheath 1 if vegetative hyphae grows up from the surrounding 

 cells. 



